If the test results of square tubes fail to meet the provisions of product standards, the unqualified ones shall be selected, and double the number of samples shall be taken from the same batch of square tubes for re inspection of unqualified items. If the re inspection results (including any index required by the test of the project) are unqualified, the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection, re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.When sand blasting or manual mechanical derusting is used, due to the falling off of the oxide scale of the galvanized square pipe, the metal on the surface of the galvanized square pipe is directly exposed in the air. If a primer is not applied in time, the surface of the galvanized square pipe is easy to rust again, affecting the adhesion of the paint film. I am engaged in all kinds of square tubes, square rectangular tubes, seamless square tubes, galvanized square tubes, galvanized tubes and other materials all year round. I operate in good faith. Welcome to call! As the paint is a time-effective material, the overstock of inventory is easy to expire. Therefore, the main indexes of the paint must be rechecked before use, and the paint can be used only when the results meet the standards.Roskeller,How about the tensile strength of square pipe: square pipe has good tensile strength, tensile strength and sufficient toughness, which makes square pipe stand out in the field of steel pipe. The square tube has great advantages in high temperature, high pressure and even high strength environment. What are its characteristics? We analyze it one by one: tensile strength (& sigma; b) the strong force (FB) borne by the sample during tensile breaking, and the stress (& sigma;) obtained from the original cross-sectional area (so) of the sample is called tensile strength (& sigma; b) and the unit is nmm (MPA).The square tube for fluid transportation (gbt-) is a general square tube for transporting water, oil, gas and other fluids.Saint-Ghislain,The second is to clean the surface of the opposite pipe. When cleaning the opposite pipe the surface should be cleaned with solvent or emulsion. Square pipes of various specifications, square rectangular pipes, seamless square pipes, galvanized square pipes, galvanized pipes are supplied in time and cost-effective. They have become the preferred brand of many wire products. Welcome to buy! It is used to remove oil and dust. It is only suitable for removing grease and dust on the surface of square pipe, which can not remove rust and oxide scale. Therefore, it can only be used as an auxiliary means in production.The advantage of empty bending is that it can bend the side length when the real bending cannot be carried out, such as synchronous bending and finishing of the upper side and side of qb square tube. Empty bend can also bend R & amp; amp; lt; .T without fracture of pipe wall.At this time, if the welding wire of the same material is used for spot welding where the thickness is insufficient, ground and sandblasted and repair welding shall be adopted where there are cracks, square rectangular tube even if the steel pipe with another large opening can be made up at one time.

The principle of straightening machine is that a disc is divided into two sides to clamp round steel straight lines. Professional square tube, seamless square tube, galvanized square tube,RoskellerMarket price of galvanized square pipe, galvanized tube, service, on-site settlement, honest operation! The edge is one with radius r, and the other outer edge must be two equal diameters with radius R. The diameter of the reinforcement to be straightened is D, and the center distance between them is adjusted to R + R + D.To sum up, improving the quality level of square tube is the key to ensure the service life of die. Therefore, when the economic cost and equipment conditions permit, the quality level of square tube, including surface quality and internal quality, should be improved as much as possible by using more mature process measures.It is good to purchase Baosteel's materials for cold drawing of square tubes because Baosteel's materials are subject to grade flaw detection, and the density of steel is relatively good. After cold drawing and heating, it is convenient to line up. The steel is cold drawn at room temperature to produce plastic deformation, so as to improve the yield strength. This process is called cold drawing strengthening. Square tube is generally used for product parts with high requirements. It has good willfulness and strength. The surface is better after cold drawing. Cold drawing principle.How much does it cost?,At this time, if the welding wire of the same material is used for spot welding where the thickness is insufficient it shall be welded to the fixed thickness, ground and sandblasted, and repair welding shall be adopted where there are cracks, even if the steel pipe with another large opening can be made up at one time.Product description of square tube square tube is a light thin-walled steel tube with hollow square section, also known as steel cold-formed profile. It is a section steel with square section shape and size, which is made of Q hot-rolled or cold-rolled strip or coil as the base material, cold bending and high-frequency welding. In addition to wall thickness thickening,RoskellerDN80 galvanized square pipe, the corner size and edge flatness of hot-rolled special square pipe reach or even exceed the level of resistance welding cold-formed square pipe. Good comprehensive mechanical properties, weldability, cold and hot workability and corrosion resistance, and good low temperature toughness.There are many ways of ignition, such as arc, electric spark, flame, strong current, high-temperature furnace, electron beam, laser, high-temperature radiation, microwave, chemical furnace, etc.

Tool derusting mainly uses tools such as steel wire brush to polish the surface of square pipe, which can remove loose or oxidized scale,Roskeller219 galvanized square pipe, rust, welding slag, etc. The derusting of manual tools can reach grade SA and that of power tools can reach grade SA. If the square pipe surface is firmly attached with iron oxide scale, the derusting effect of tools is not ideal and can not reach the anchor depth required by construction.Manufacturing cost, so the deformation angle & theta; It can accurately reflect the deformation degree of corners and edges. In the design process, considering the influence of dimensional accuracy and metal work hardening, the distribution of deformation angle is usually larger at the beginning and middle passes, and then gradually decreases. In the pass formed directly by arc intersection, the fillet part of the pipe blank cannot be filled with the pass, so the pass perimeter is different from that of the pipe blank. In order to ensure the dimensional accuracy, the fillet part of the pass needs to be corrected and calculated. Therefore, this method has higher design accuracy than other methods. However, this method is more suitable for pass design by computer. If you use a frame that deforms both horizontally and vertically, you can directly use the deformation angle & theta; Pass design.With the progress of the times, square tubes are used in more and more fields, and their scope of use is obviously increasing, which makes us have many kinds of square tubes. At this time, and the size and thickness are not standardized, it can reflect that this square tube is a poor product& rdquo;Roskeller,QB square tube is a product appeared in recent years, which mainly has strict tolerance and roughness for the dimensions of inner hole and outer wall. Production process classification of large-diameter qb square tube large-diameter qb square tube is divided into hot-rolled seamless square tube, cold drawn seamless square tube, seamless square tube and qb square tube according to production process. Among them, qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Material classification of straight seam welded square pipe and spiral welded square pipe large diameter qb square pipe: plain carbon steel square pipe and low alloy square pipe. Ordinary carbon steel is divided into Q Q q SS, # steel, # steel, etc; Low alloy steels are divided into q Mn, Q, St-, etc.Superior square tubular steel (both P and s ≤ .%)Among them, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Straight seam welded square pipe, spiral welding